Sand-blast machinery.



No. 727,030. T PATENTED bananas; B. o. TILGHMAN, Jn..

SAND BLAST MACHINERY.

APPLICATION TILED JULY 8, 1902.

N0 MODEL. 8 SHEETS-SHEET 1.

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PATENTED MAY 5, I903.

B. G. TILGHMAN, JR. SAND BLAST MAGHINERY. APPLIOAI'IOR' FILED JULY 8, 1902.

8 SHEETS-SHEET 2- N0 MODEL.

PATENTED MAY 5, 1908.

B. c. TILGHMAN, JR. SAND BLAST MACHINERY. APPLIUATIOH FILED JULY 8, 1902.

8 SHEETS-SHEET 3.

H0 MODEL.

5 Philadelphia,

' Patented May 5, 190a BENJAMIN GUTILGHMAN, Ja, or Pui DELPnIA, PENNSYLVANIA.

[SAND-BLAST MACHIN ERY.

ssacrnde'rrou forming part of To all whom it may concern:

, Be it known that I, BENJAMIN G. TILGH- MAN, Jr., a citizen of the United States of America, residing in the city and county of have invented certain new and useful Improvements in Sand-Blast Machinery, of 1 which the following is a true and exact description, reference being bad to the accoml0, panying drawings, which form apart thereof.

2o ratus, and I o atmosphere that is not exposed to 5 nected to supply sand to My invention relates to sand-blast machinery, and has for its object to simplify the construction of such machinery and at the same time to facilitate the even flow of sand to the combining-chamber.

A special object of my invention is to dispense with the use of air-locks and of airtight sand-admission valves, such as are commonly employed in pressure sand-blast appahave also generally in view the avoidance by the use of novel devices and combinations with in the use of such machines.

The leading feature of my invention consists in the use, in combination with a combining-chamber in which a current of air under'pressnre mixes with and from which it sweeps the sand to a point of use, of a feedcondnit having its top, in effect, open to the the pres sure existing in the combining-chamber, said conduit being adapted to contain a column of sand of a weight greater than the pressure of air in the through which it flows into the combiningchamber and having its lower-end exposed to the pressure of the air in the col-shiningchamber or connected parts. By preference,

. and this is in practice of great importance,

( 5 plied to the'iower end of the feed-conduit should have an opening or openings for the admission of the high-pressure air separate and distinct from the feed-orifice by which the sand is supthe combining-chamber, and for the best results the construction should be such .that the air-pressure at the feed-orifice is practically balanced; These conditions are conveniently secured by causing the feedconduit to deliver its sand into a hopper-like chamber, from which in turn the feed-orifice leads, the upper part oi the hopper being in the State of Pennsylvania,

of difliculties heretofore met' com bining-chamber and being conthe orifice 0r orifices I Letters Patent No. 721,030; dated. May 5, 1903. Application filed July 9, 1202. Serial no. news. on model.)

open to the air-pressure, as is the lower part of the feed-conduit.

Another important feature of my invention consists in providing, in connection with the feed-conduit, means .for heating it and the sand within it so as to maintain the sand at such a temperature as will prevent the condensation of moisture within it. This is highly important, because there is a constant current of air passing upward through the feedcondnit and diminishing in pressure as it rises, with the natural resultot' tending to deposit moisture, and such deposited moisture will of course soon prevent the natural and proper flow of the sand.

Another feature of my invention is designed to overcome difiiculties met with in sand blast apparatus owing to the blocking up of the feed-orifice leading to the combiningchamber. This is a not infrequent occurrence and is due to many causes, and I obviate this diliiculty by providing in or close to the orifice where stoppages occur a slot and in said slot a sliding plate having one or more orifices which can be made to register with the'feed-orifice and which by moving the slide can be shifted to a position in which they dump any material contained in them.

By preference I make this slide with abutments which at the extremes oi its movement, which facilitates the discharge of material contained in the orifice and also the restablishing of a flow of sand from the hopper. J

Another feature of my invention, designed especially to obviate stoppages in the feedconduit due to the tendency of the sand to arch, is Aheprovision of a rod extending through the feed-conduit in the line of flow of sand and movable therein, by means of which this arching of the sand can be prevented or overcome. The rod may be moved either longiludinallyor by rotation.

Other features of my improvements will be best understood as described in connection with the drawings, in which they are illustrated, and in which drawings- Figure 1 is a sectional elevation of a sandblast apparatus constructed in accordance with my invention and embodying my improvements in what I believe to be its best commercial form. Fig. .2 is a cross-sectional strike against the feed-hopper and Fig. 9 is a view showing a modification air under pressure and sand lating-gate for adjusting the sand-delivery nozzle. In Figs. 2 and 3 it is operated by means of a hand -1ever F, the adjustable screw F being provided to regulate the size of the orifice, thelever being moved freely in the other direction to cut oi the supply of In Fig. 4 the adjustment and all movements of the gate or valve F isanade through anut (indicated at F) workingon the threaded end of the rod attached to the gate.

B (shown in Figs. 2, 3, and 4) is a slot formed, as shown, immediately above the oriview on the line 2 2 of Fig. 1; Fig.3, a similar view showing the slidein the alternative position to that shown in Fig. 2. ig. 4 is asimilar view illustrating a modification in the slitie construction. Figs. 5, 6, 7, and 8 are sec ional elevations showing various modifications embodying my improvements,

within my invention.

A indicates the combining-chamberthat is to say, the place where the air mixes with the sand and begins the work of carrying it along through the conduit to the point of debining-chambers, as shown in Figs. 1, 5, and 8, are substantially alike. In Fig. 6 the com bining-chamber (indicated at a) is the on ber E throughwhich the sand falls, and in 7 the combining-chamber (indicated at a) is of still a dilferent construction. I

provided with a transverse opening, (indicated at G,) which can be made to register with the feed-orifice, as shown in Fig. 2, or shifted with the slide to one side, as shown in Fig. 3.

G2 is a rod by which the slide is moved, and G and G abutments formed which strike against the edges of the hopper at the extremes of its movement, not only limiting the movement of the slide, but giving abrupt jar both to the slide and to the In the construction shown in Fig. 4 provided with two openings, (in-- dicated at G and g,) which are alternately moved into registration with the sand-orifice as the sand is shifted from one side to the other. v v

His the feed-conduit, which, as shown in Figs. 1, 5, 6, 7, and 8, is open at the top and, as shown, provided with a hopper H, the lower end of the conduit opening either into the combining-chamber, as indicated in Fig. 8, or into some connection having the same pressure as the pressure-chamber O, as in Figs. 1, 6, and '7, or into the closed hopper B as shown in Fig. 5. In Fig. 9 the upper end of the conduit II connects bya spout L with the hopper L in which the-pressure leads the conduit E, comlng from the comor machine, (indicated at E.)

B is the hopper by which the combiningchamber is fed with sand through a feed-orifice, (indicated at B.) The top of the hopper is open, as indicated at B and it is inclosed in the pressure-chain her 0, from which the air enters the combining-chamber.

In the construction tion C made from the supply-pipe E, which in this case connects directly with a combining-chamber to the upper part of the hopper, (here indicated at B the top of which in this construction is closed,and in Fig.8 the equivalent of the hopper is found in the contracted end I) of the feed-conduit H, 19 indicating an opening into the feed-conduit above and to the side of the nozzle through which the sand entersthe combining-chamberA. In Fig.6the feed-conduit H connects with a base-casting B havinga hopper-shaped bottom terminating in a feed-orifice, the conduit H having one or more openings b formed in its lower end for air, and the escape of sand from such opening being prevented by shelves, such as B thrown out below said openings.

In Fig. 7ahopper(in'dicated MB) is shown; but itis suificiently similar to the hopper indicated in Fig. l to need no special description except to note that the sand issues from the hopper through an annular series of openings, (indicated at b,) the delivery-pipe passing out through the hopper through the center of the series of feed-orifices;

D indicatesthe conduit through which the pass to the delivery-nozzle D. In Figs. 1, 5, (1', and 8 the conduit is represented as a hose with a contracted delivery-nozzle, and in Fig. 7 the conduit (marked 01) is shown as an upright metal pipe ha'vinga delivery-nozzle at its upperend.

F (best shown in Figs. 2, 3, and 4) is a reguand theoretically a somewhat heavier column of sand in conduit H would be necessary to overcome the pressure umn. The constructions are, however, practically equivalent, and my'invention includes weight of the sand column is utilized to overguished from the old constructions, in which the air under pressure is admitted to the top of the feed-box to balance the pressures acting on the sand therein. feed-conduit must in all cases be such as will enable it to be kept charged with a column of sand the weight of which above the point where the conduit is exposed to the pressure sand in the conduit, but only result in the escape of a certain, limited amount of'compressed air through the mass of sand. 7

I, Figs. 1 and 7,indicates a rod extending through the feed-conduit in the line of movement of the sand and which can be moved on the slide,

would be somewhat less than atmospheric,

at the base of the co1-' The height of the in its scope any modification in which the I come the airpressure at its base, as distinber L, and a suction-pipe K either vertically, as by means of a lever I, (see Fig. 1,) or rotatable,'as by means of a hand-wheel and gear, as shown at I in Fig. 7..

J is a steam-jacket surrounding the feedconduit H, J

indicating a steam-supply entering it, and J a drip-pipe leading from its bottom.

K is a grating forming the floor of the chamber or place where the sand-blasting is done and which permits the sand to escape through it into a hopper-shaped chamber K, having a spout K, which leads to a combining-chamto the combining-chamber L.

L indicates the upwardly-extending tube of a pneumatic elevator, opening into a chamber L at top, from which chamber leads a conduit L connected with the suction-fan L L is a baffle-plate placed im mediately above the top L of the tube L. v

L is a spout leading from the bottom of the chamber L into the hopperH' of the feeds conduit H, L indicating a gate for this spout.

M indicates the object to which the sand blast is being applied.

In the operation of the apparatus'indicated in Fig. 1 the blower or compressor E forces air under pressure through the pipe E into the pressure-chamber 0, from which it passes through the opening A into the tube making up the combining-chamber A and through itand the tube D and nozzle 1). The sand is charged into the feed-conduit H, filling the hopper B below it and filling the feed-conduit to a height which, as before stated, will secure a column of sand above the lower end of the conduit, which will exert a pressure per square inch at that point greater than the pressure of the pressure fluid. The sand passes downward through the opening B" to the slide G and through the feed-orifice in the slideinto the combining-chamber and is swept along with the air to the nozzle, fresh sand coming into the hopper from the feedconduit to make up for the amount delivered through the feed-orifice. A certain amount of the pressure fluid will of course escape upward through the sand in the feed-conduit, diminishing in pressure as it rises, and consequently tending to deposit moisture and to diminish the temperature of the sand column. This tendency, however, is counteracted by the heating of the sand column, which is most conveniently efiected by a steam-jacket J, but obviously can be eifected in other well-known ways. vice which will keep the sand in the feedconduit at proper temperature is the full equivalent for the steam-jacket. The tendency of the sand to arch in the feed-conduit, and thus arrest or check the flow of sand, is counteracted by the red I, which may be either moved vertically, as by the lever I in Fig. 1, or rotatable by the handswheel I in Fig. '7, in either case effectually preventing or overcoming the tendency to arch. The tendency of the feed to choke is overcome by which also leads I spout L In fact, any demeans of the slide G, which when a totalor partial choking is observed is moved by the rod G: cutting out the sand or other material contained in the opening G and permitting iit to drop outside of the'combining-chamber-,-as, for instance,

would be the case when the'slide is shifted from the position shown in Fig. 2 to that shown in Fig. 3. The sand from the nozzle which falls upon the grated floor K passes throu h it to the hopper K and thence through the spout K to the combining-chamber L. Air at the same time enters the bottom of the combining-chamber, preferably sucked from the sand-blast chamber and, as shown, through the bottom of the chamber K, through the pipe K and its connection K, and theair-current, carrying the sand with it, passes upward through the pneumatic lift-pipe L, issuing from its top I? against the baffle-plate L, and falling into the chamber L into the chamber L and suction-fan L and the sand collecting in the chamber L is permitted to issue through the into the hopper H, supplying the feed-conduit H, the apparatus being thus rendered automatic and self-supplying.

The operation of the modification shown in Figs. 5, 6, and 7 is sufliciently obvious to need no further description; but as to the modification of Fig. 8 I will note that the platform 0 is supplied surrounding the contracted nozzle b of the feed-conduit H to form an arresting-floor for the sand which issues through the lateral orifices, (indicated at b and which orifices are supplied for the entrance of air to the bottom of the feed-conduit and to avoid an upward draft of air through the feed-orifice for the sand.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, isi 1. In a sand-blast machine having a combining chamber intowhich the sand and pressure fliiid flow and mix and from which the mixed fluid andsand are led for use,said

chamber having a'passage for the entrance of sand, the combination therewith of a sandfeed'conduit arranged to deliver sand to the said passage and in free communication with said chamber at its base, said feed-conduit being at the top free from the pressure in the combining-chamber and extending above its base connection with said chamber to a height which will give a sand-pressure at the chamber connection in excess of the fluid-pressure at the same point, and a restricted sand-blast nozzle through which the mixed sand and fluid issues from the chamber and by means of which the pressure in the chamber is maintained at a considerable degree above atmospheric pressure. A

2. In a sand-blast machine :having a combining-chamber into which the sand and pressure fluid flow and mix and from which .the'

mixed fluid and sand are led for use, said chamber having'a passage for the entrance of sand, the combination therewith of a sand- 5 combining-chamber andextending above its base connection with said chamber to a height which will give a sand-pressure at the chamber connection in excess of the fluid-pressure at the same point, and'means for heating the sand as it descends through the sand-feed conduitto prevent the condensation of moisture therein.

3. In a sand-blast machine, ai'eed-conduit for sand adapted to contain a solid column and delivering its sand to a combining-chamber in comb' through the feed-conduit and ing said rod sand.

nection'with the chamber ,to a height which will give a sand-pressure at thejchamber conuection in excess of the fluid-pressure at the same point, and a rodextending through the central part of the feed-conduit and movable therein. 5.. In a sand-blast machine havin'g'a chamber into which the sand and pressure fluid flow and mix and from which the 'mixed fluid and sand are led for use, said chamber having a passage for the entrance of sand, the combination therewith of a sand-feed conchamber at its base, said feed-conduit being at the top free from the pressure in the combining-chamber and extending above its base connection with the which will give a sand-pressure at the chamber connection in excess of the fluid-pressure at the same point, a rod extending part of the feed-conduit and movable therein and means for heating the sand in said feed-conduit to prevent condensation of moisture therein. 4

6. In a sand-blast machine having a chamber into which the sand and pressurefiuid flow and mix and from which the mixed fluid and sand are led for use, said chamber havthan the feed-opening into the chamber, said fpressure in the combining-chamber and exchamber to a height f her and a connection from its upper end to the combining-chamber for the passage of the pressure fluid, a sand-feed conduit opening into the hopper and at the top free from the pressure in the combining-chamber, said conduit extending above its opening into the hopper to a distance which will give a sandpressure in excess of the-fluid-pressure atits said opening. H

In a sand-blast machine havinga chamher into which the sand and and sand are led for use, ing a passage for the entrance of sand, the

combination therewith of a sand-feed con- 'duitarranged to'deliver sand to the said opening and having a base connection with the chamber other than and at a higher level than the feed-opening iuto'the chamber, said feed-conduit being at the top free from the pressure in the combining-chamber and extending above its base connection with the chamber to a'height which will give avsaudpressure at the chamber-opening in excess of fluid-pressure att-he same point and means for heating the sand in the feed-conduit to prevent condensation of moisture therein.

9. In a sand-blast machine having a chamber into which the sand and and sand are led for use, ing a passage for the entrance of sand, the

in the combining-chamber and above its base connection with the chamber to a height which will give a. sand-pressure at the chamber-opening in excess of the fluidpressure at the same point, and a jacket surrounding the feed-conduit.

In a-sand-blast machine the combinamaintained a considerable degree above atmospheric pressure, a feed-conduit arranged to supply sand to the feed-passage and of a height sufficient to maintain a sand column having a pressure at its base connection with heatingextending the chamber greater than the fluid-pressure thereat, ahopper arranged to receive the sandblast after it is used, an elevated receptacle for the sand arranged to supply sand to the feed-conduit and mechanism acting to elevatethe sand received in the hopper for used sand and deliver it to said elevated chamber.

11. In a sand-blast machine the combination of a combining-chamber for pressure fluid and sand, said chamber having a passage for the entrance of sand, a restricted sand-blast nozzle through which the mixed sand and fluid'issue and by means of which the pressure in the combining-chamberis maintained a considerable degree above atmospheric pressure, a feed-conduit arranged to supply sand to the feed-orifice and of a height suflicient to maintain a sand column having a pressure at its base connection with the chamber greater than the fluid-pressure thereat,'a hopper arranged to receive the sandblast after it is used, a pneumatic sand-lift and elevated hopper to receive the sand from saidlift and a conduit from said elevated hop per to the top of the sand-feed conduit.

12. In asand-blast apparatus havingacombining-chamber for pressure fiuidand sand,

said chamber having a passage for the entrance of sand thereto, the combination there- I with of a feed-conduit for supplying sand to said passagega transverse slot leading across said passage and a slide moving in said slot and having a passage formed therethrough which in one position of the slide coincides with the feed-passage and in another position opens freely outside of said passage.

13. Ina sand-blast apparatu s having a com- I pining-chamber for pressure fluid and sand, said chamber having a passage for the entranceof sand thereto, the combination therewith of a feed-conduit for supplying sand to said passage, a transverse slot leading across said passage and a slide moving in said slot and having a passage formed therethrough which inoneposition of the slide coincides with the feed-passage and in another opens freely outside of said passage, said slide having also an abutment or abutments arranged to strike'against a portion of the apparatus at the end of one or both movements.

13'. O. TILGHMAN, JR. Witnesses:

CHAS. E. MYERS, D. STEWART. 

